PROJECT SUMMARY/ABSTRACT In 2016, the prevalence of tobacco use was 15.5% among adults in the United States. Developing effective cessation interventions remains a public health priority, and mHealth offers the opportunity to reduce barriers to dissemination and implementation of cessation treatment. This Stage 1 treatment development project tests the potential of the emerging technology of augmented reality (AR) as the basis of an adjunct treatment for tobacco dependence. AR is a rapidly-advancing technology that could provide a novel and exciting aid to smoking cessation. AR inserts virtual, digitally-created objects into the real-world environment as viewed on a screen (i.e., smartphone or tablet). With respect to health promotion interventions, AR provides the opportunity to extend therapeutic elements into the user's own environment. As such, AR seemingly provides the perfect opportunity for extinction-based treatment in the real-world. Cue-exposure treatments have demonstrated efficacy for decreasing tobacco craving in the laboratory or clinic, but these effects are often short-lived, and do not appear to generalize beyond the extinction setting. This post-extinction ?renewal effect? has been demonstrated in both animal and human studies. With the emergence of AR technology, it is now possible to conduct extinction trials across multiple environments throughout smokers' own real-world smoking settings. The potential to extend the effects of cue-exposure to the everyday environment, combined with the widespread use of smartphones, presents the opportunity to develop an innovative and scalable smoking cessation treatment. The primary goal of the proposed project is to initiate a systematic line of research by creating a set of smoking-related and comparison neutral AR stimuli, and then testing their ability to produce cue-reactivity and extinction in the laboratory. This project has three aims. Aim 1 will develop an AR mobile app and pilot test the AR smoking and neutral stimuli on a small sample of smokers. We will then modify the stimuli based on their feedback. Aim 2 will comprise two, lab-based sessions to test the impact of AR stimuli on cue-reactivity and extinction of smoking urges, respectively. The cue-reactivity session will utilize a 2x2 within- subjects factorial design to test AR smoking stimuli against both neutral stimuli and in vivo stimuli on self- reported urge to smoke. The second session will involve repeated presentations of the AR smoking stimuli to test for extinction. If AR stimuli demonstrate sufficient cue-reactivity and extinction in the laboratory, subsequent research would extend this work into the real-world to determine the ability of AR to impact urges and smoking behavior. Thus, Aim 3 will upgrade the app for therapeutic use and pilot test the AR smoking stimuli in the real-world environment to prepare for a future, larger-scale trial. This project is expected to validate AR as a strategy for conducting extinction trials that form the basis of cue-exposure therapy and set the stage for a randomized controlled trial to test AR as a component of a more comprehensive smoking cessation intervention.